Dial plates for timepieces

ABSTRACT

A dial plate for timepieces consisting of a metallic base plate and a thin shell plate having a nacreous gloss and bonded to said metallic base plate with the nacreous surface thereof exposed to the outside by means of an adhesive, in which said thin shell plate is bonded to said metallic base plate at an opaque layer formed on said thin plate or plating applied to the back side thereof.

United States Patent Takagi et al.

DIAL PLATES FOR TIMEPIECES Inventors: Tooru Takagi; Tsuneyoshi IShinoyama; Setsuo Satoh, all of Tokyo, Japan Assignee: Orient Watch Co.,Ltd., Tokyo,

Japan Filed: Sept. 26, 1972 Appl. No.: 292,322

Foreign Application Priority Data Dec. 8, 1971 Japan 46/9915! Apr. 17,1972 Japan 47/38485 Us. Cl. 58/127 R, 58/88 0 Int. Cl. G04b 19/06 Fieldof Search 58/88 G, 127 R; 29/177 Jan. 22, 1974 [56] References CitedUNITED STATES PATENTS 3,633,355 1/1972 Sakala 58/127 R PrimaryExaminer-Richard B. Wilkinson Assistant Examiner-Edith Simmons JackmonAttorney, Agent, or Firm-Richard K. Stevens et al.

[5 7] ABSTRACT A dial plate for timepieces consisting of a metallic baseplate and a thin shell plate having a nacreous gloss and bonded to saidmetallic base plate with the nacreous surface thereof exposed to theoutside by means of an adhesive, in which said thin shell plate isbonded to said metallic base plate at an opaque layer formed on saidthin plate or plating applied to the back side thereof.

6 Claims, 3 Drawing Figures DIAL PLATES FOR TIMEPIECES This inventionrelates to dial plates for timepieces and more particularly to dialplates, for timepieces, having a remarkable decorative effect which isbrought about by ingenious use of the aesthetic characteristics ofshells.

Conventional dial plates for timepieces such as a watch, a wrist watch,a bracelet watch, a pendant watch and a finger ring watch are generallycomprised of a base plate consisting of a brass plate or aluminum plateand color coating or plating layers applied thereto. A dial plate is oneof the exterior accessories of portable timepieces which is attractiveto the taste of the users and for which the aesthetic effect is requiredmost. In this view, dial plates of various patterns and colors have beenprovided for said timepieces heretofore but the coloring of dial plateshas provided only a limited variation in pattern and color, and beenunable to sufficiently satisfy the demand for entirely novel dialplates. There has been known a so-called shell-enchasing technique inwhich iridescent flakes of shells are embedded in the lacquer surfacelayer of an article such as a paper container box or.a cake bowl toproduce a decorative effect, and various studies are beingmade in recentyears on the application of such technique to portable timepiece dialplates toimpart a decorative effect to the dial plates and thereby toenhance the commercial value of timepieces. However, in the conventionalshell-enchasing technique an embedding method has in most cases beenemployed for securing the shell flakes to a.substrate and such a methodcannot be directly used in the manufacture of portable timepiece dialplates which are required to be as thin as possible. Under thecircumstances, a method has been provided in which a thin sheet of shellmaterial is laminated on the base plate of a dial plate by means of anadhesive or the like, but this method has had the disadvantage that anirregularity in application of the adhesive isvisible through thelaminated shell flake since the shell flake is extremely thin andsemi-transparent, resulting in degradation of the aesthetic effect ofthe shell, and the method hasnot been applied in practical use.

There has also been proposed a dial plate for high grade portabletimepieces which is made from a jewel such as ruby or sapphire per se.However, such a dial plate is extremely expensive and, in addition, theworking on the jewel is extremely difficult because of its high hardnessand especially the boring of small holes in the jewelry dial plate forimplanting indexes or the like is difficult. Therefore, in such type ofdial plate the time marks have in most cases been printed on the surfaceof the dial plate, but the printing of the time marks has provedunsatisfactory not only in that the printed marks are illegible but alsoin that a variety of time indexes cannot be used.

It is therefore the object of the present invention to provide noveldial plates for use in high grade portable timepieces, which areentirely different from and overcome the disadvantages of theconventional dial plates, which have a remarkable aesthetic effect andwhich can be produced in a mass production with ease and at low costs.According to the present invention there can be obtained dial plateswhich individually have different patterns andcolor hues to each otherand hence each of which has a marked originality.

According to one aspect of the invention there is provided a dial platewhich comprises a thin metallic base plate made from metal such as brass'or aluminum and a thin plate of shell material laminated on saidmetallic base plate by means of applying adhesive, the bonding surface(hereinafter referred to as back surface) of said plate of shellmaterial or shell flakes (hereafter shell plate) with said metallic baseplate being coated with a non-transparent coating layer, whereby anirregularity, if any, in application of said adhesive is not visible onthe front surface of the dial plate and further the color hue of saidpaint layer and the optical refraction of the shell are ingeniouslycombined to produce a highly variable aesthetic effect. There is alsoprovided a dial plate of the character described above, in which thesurface (hereinafter referred to as front surface) of said thin shellplate is coated with a transparent or semi-transparent coating layer,whereby a unique change of color hue and gloss can be imparted to thedial plate. These optical effects are due to the combination effect ofthe ray reflected on the surface of the shell plate with the rayreflected on the surface of the transparent or semi-transparent coatinglayer. There is also provided a dial plate of the character describedabove, in which small holes are bored through the laminate of said thinshell plate and said metallic base plate, and separately provided typesare implanted in said small through-holes.

According to another aspect of the invention there is provided a dialplate which comprises a thin metallic base plate made from brass oraluminum and a thin shell plate laminated on said metallic base plate bymeans of an adhesive, the bonding surface of said shell plate with saidmetallic base plate being plated by an electroless plating, whereby anirregularity, if any, in application of said-adhesive is not visible onthe surface of the dial plate and further the color hue of saidnonelectrode plating and the optical refraction of the shell areingeniously combined to provide a highly variable aesthetic effect.There is also provided a dial plate of the character described above, inwhich the front surface of said thin shell plate is coated with atransparent or semitransparent coating layer, whereby a unique variationof color hue and gloss can be imparted to the dial plate. There is alsoprovided a dial plate of the character described above, in which smallholes are bored through the laminate of said thin shell plate and saidmetallic base plate, and separately provided types are implanted in saidsmall through-holes.

The present invention will be described by way of example hereunder withreference to the accompanying drawings, in which:

FIG. 1 is a top plan view of an embodiment of the dial plate accordingto the present invention;

FIG. 2 is a vertical sectional view, partially broken away, of the dialplate taken on the line IIII of FIG. 1; and

FIG. 3 is a fragmentary sectional view, partially broken away, ofanother embodiment of the dial plate according to this invention.

Referring to the drawings, a base plate 1 of the dial plate is made froma thin metallic sheet, such as a brass or aluminum sheet, by punching.The base plate 1 has legs la by which the dial plate 1 is secured to thewatch movement (not shown). The base plate 1 is provided with a hole orperforation 1b at the center thereof for receiving the spindles of hour,minute and/or second hands (not shown) of the timepiece therein. A thinshell plate 2 is superimposed on the base plate 1, which is obtained bypeeling the nacreous layer of a shell by a known method to make flakes.The thin shell plate 2 has a disc shape essentially same as the shape ofthe base plate 1 and is provided with a hole 20 at the center thereof inalignment with the hole 1b of the base plate 1. As the materials of thethin shell plate, the shells of shellfishes such as ear-shells, pearlshells, Mexican shells, black lips, yellow lips and other iridescentshells are suitably used. The shell plates made from said shellsrespectively have different optical tastes. The back side of the thinshell plate is coated with an opaque paint layer, such as a lacquerlayer, or an electroless plating layer 3. The opaque coating layer 3 canbe of an optional color hue and its color tone can be freely selectedover a wide range. Further, the back side of the thin shell plate can becoated not only with a single paint of certain color but also with acombination of paints of different colors. On the other hand, where theback side of the thin shell plate 2 is coated with an electrolessplating layer, such an electroless plating layer may be depositeddirectly on said thin shell plate. As the metals which can be used forthe electroless plating layer there can be mentioned single metals suchas nickel, cobalt, copper, silver, gold and platinum, and alloys such asnickel alloys and cobalt alloys. A remarkable decorative effect can beobtained particularly when silver or gold is used. By properly selectingthe metal to be used, the color tone of the electroless plating layercan be optionally changed. Further, the back side of the thin shellplate can be coated not only with a single plating of certain color butalso with a combination of platings of different colors.

The thin shell plate 2 described above is fastly adhered to the baseplate 1 by means of an adhesive layer 4. As the adhesive, epoxy typeadhesives which are widely used can be employed by the adhesive to beused is of course not limited only thereto. Although in the embodimentshown the adhesive layer 4 is provided over the entire area of theoutside surface of the base plate 1, it has been revealed throughtesting of the actual product that the provision of the adhesive layeronly at several locations on the base plate 1 is sufficient to preventdisengagement or distortion of the thin shell plate 2. Reference numeral5 designates time markings provided on the surface of the dial plate,which are directly printed on the surface of the thin shell plate 2.

In the dial plate for portable timepieces according to the presentinvention, as described above, the opaque coating layer or electrolessplating layer 3 are provided on the back surface of the thin shell plate2, so that the adhesive layer provided between the surface of the baseplate and the thin shell plate is not visible through said thin shellplate, and therefore, said thin plate 2 can be directly bonded to thebase plate 1.

Namely, when the dial plate is viewed squarely from the front sidethereof, an irregularity, if any, in application of the adhesive is notvisible through the shell plate as it is covered with the opaque coatinglayer or electroless plating layer 3 and, therefore, the aestheticeffect of the dial plate is not impaired. Consequently, it isunnecessary to exercise unnecessary care during production of the dialplate and the dial plate can be produced by mass production system withease. The aesthetic effect of the dial plate is brought about by thecombined effect of the nacreous color and optical refractioncharacteristic of the thin shell plate 2 and the opaque coating layer orelectroless plating layer 3. Thus, a high colorful dial plate emitting avariety of color lights can be obtained. Dial plates for use in portabletimepieces are required to be as thin as possible. In this respect, thedial plate can be formed in the shape of a thin plate as a whole, as theshell plate 2 is adhesively bonded directly to the base plate 1. Namely,in the embodiment shown, the base plate 1 has a thickness of 400 micronsand the shell plate 2 has a thickness from 200 to 250 microns so thatthe entire thickness of the dial plate may be as small as not greaterthan 700 microns. This brings about the additional advantage that usualapparatus for producing dial plates for thin portable timepieces can beused as such for the production of the dial plate of this invention.

FIG. 3 shows another embodiment of the dial plate according to thisinvention. This embodiment is similar to the preceding embodiment inthat the thin shell plate 2 having the back surface thereof coated withopaque paint layer or electroless plating layer 3 is laminated to thebase plate 1 by means of the adhesive layer 4, but is different from thepreceding embodiment in that the front surface of said thin shell plate2 is also coated with a paint layer 6. The paint layer 6 is formed of atransparent lacquer, semi-transparent lacquer or industrial varnish, andimparts various changes to the surface gloss of the plate 2 and slightlycolors said plate. By properly selecting the coating materials used, analmost infinite number of color combinations can be obtained. It hasbeen confirmed on the actual dial plate that, by applying the coating ina vignette type, a dial plate having a highly fantastic aesthetic effectcan be obtained, and that the paint when applied uniformly on the plateof shell produces an iridescent pattern. It is also effective to applythe paint in such a manner that the color darkness of the paint isprogressively increased'toward the peripheral edge from the centralportion of the dial plate where the coating layer is transparent.Reference numeral 7 in FIG. 3 designates time marking types provided onthe front surface of the dial plate, which are separately made of such ametal as brass and coated with a plating, and are secured to the dialplate at its legs 7a which are extended in small holes, bored throughthe shell plate 2 and base plate 1 and fixed therein as by spot welding.The thin shell plate 2 of the dial plate according to the presentinvention is lower in hardness than jewelries, such as ruby, andtherefore, can be worked relatively easily. The through-holes can bebored therein also by a conventional boring machine. This alsofacilitates the mass production of the dial plate without adding to theproduction cost.

As described hereinabove, the dial plates for timepieces, according tothe present invention exhibit a variety of colors and patterns which arebasically created by the nacreous color possessed by the shell and arevariable in an indefinite number of ways in combination with the coloror colors of the paint or paints used in a variety of ways, and whichgive a sense of quality to the dial plate. In addition, the dial platesof the invention can be produced in large quantities at low costs andthe product dial plates individually have different aesthetic effects oftheir own and are entirely novel. It should be noted that the dialplates of the invention are not necessarily of round shape as shown inthe embodiments but may be of square or rectangular or any otherirregular shapes, and are of great practical commercial value.

What is claimed is:

l. A dial plate for timepieces, of the type comprising of a laminate ofa thin metallic base plate and a thin shell plate bonded thereto bymeans of an adhesive, characterized in that said thin shell plate isadhered to said thin metallic base plate at an opaque layer applied tothe substantially entire area of the back surface of said thin shellplate.

2. A dial plate for timepieces, according to claim 1, wherein the frontsurface of said thin shell plate is provided with a transparent coatinglayer.

3. A dial plate for timepiece, according to claim 1, wherein the frontsurface of said thin shell plate is provided with a semi-transparentcoating layer.

4. A dial plate for timepieces, according to claim 1, wherein saidopaque layer is formed by means of an electroless plating. v

5. A dial plate for timepieces, according to claim 1, wherein saidopaque layer is formed by coating of opaque paints.

6. A dial plate for timepieces, according to claim 1, wherein thelaminate of said thin shell plate and said base plate is formed withsmall through-hole and time marking types having mounting legs aresecured to the front surface of said thin shell plate by inserting saidmounting legs into said small through-holes.

1. A dial plate for timepieces, of the type comprising of a laminate ofa thin metallic base plate and a thin shell plate bonded thereto bymeans of an adhesive, characterized in that said thin shell plate isadhered to said thin metallic base plate at an opaque layer applied tothe substantially entire area of the back surface of said thin shellplate.
 2. A dial plate for timepieces, according to claim 1, wherein thefront surface of said thin shell plate is provided with a transparentcoating layer.
 3. A dial plate for timepiece, according to claim 1,wherein the front surface of said thin shell plate is provided with asemi-transparent coating layer.
 4. A dial plate for timepieces,According to claim 1, wherein said opaque layer is formed by means of anelectroless plating.
 5. A dial plate for timepieces, according to claim1, wherein said opaque layer is formed by coating of opaque paints.
 6. Adial plate for timepieces, according to claim 1, wherein the laminate ofsaid thin shell plate and said base plate is formed with smallthrough-hole and time marking types having mounting legs are secured tothe front surface of said thin shell plate by inserting said mountinglegs into said small through-holes.